cve/2020/CVE-2020-28974.md

### [CVE-2020-28974](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-28974)
![](https://img.shields.io/static/v1?label=Product&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=n%2Fa&color=blue)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=brighgreen)

### Description

A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height.

### POC

#### Reference
- http://www.openwall.com/lists/oss-security/2020/11/25/1
- http://www.openwall.com/lists/oss-security/2020/11/25/1
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9.7
- https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.9.7
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3c4e0dff2095c579b142d5a0693257f1c58b4804
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=3c4e0dff2095c579b142d5a0693257f1c58b4804
- https://seclists.org/oss-sec/2020/q4/104
- https://seclists.org/oss-sec/2020/q4/104

#### Github
- https://github.com/ZIllR0/Routers